a. Field of the Invention.
This invention relates to water purification devices in general and more specifically a small, compact water purification plant employing a novel timing mechanism for controlling a backwashing cycle.
B. Description of the Prior Art.
Applicant is not aware of any device such as the one herein disclosed for initiating, controlling the duration of, and stopping the backwashing cycle of a water purification apparatus. Most prior art water purification apparatus whether large or small depend on electric clock-type timers for controlling the backwash cycle for the filter media. Such electric timers initiate the backwashing cycle after the passage of a certain period of time. This period of time may be totally unrelated to the actual need of the filter for backwashing which is normally a function of the amount of water that actually passed through the filter media as well as the specific chemical nature of the unpurified water supplied to the apparatus.
Other devices for initiating the backwash cycle of filtering apparatus measure the amount of water actually filtered. Such devices are very expensive in themselves and contribute significantly to the overall cost of any apparatus in which they are employed.
It is therefore the primary object of the present invention to provide a compact water purification plant having a novel device for initiating, controlling the duration of and stopping the backwashing cycle in response to the actual amount of water filtered by said plant.
It is another object to provide such a control device which is simple in its construction and extremely reliable in its operation.
It is a still further object to provide such a control device which is inexpensive to manufacture when compared to devices of the prior art for performing the same function.
Other objects and advantages will be apparent and understood from the following description and drawings.